Senate Republicans are gearing up to go nuclear in response to a planned Democratic filibuster of President Donald Trump’s nominee to the Supreme Court, Neil Gorsuch.

By deploying the so-called “nuclear option,” Republicans will modify Senate rules to remove the 60-vote threshold required to end debate on a Supreme Court nominee, allowing Gorsuch and any future nominees to be confirmed with a simple 51-vote majority.

Senate Majority Leader Mitch McConnell said Tuesday he has secured the votes required for the nuclear option, but there’s one Republican senator who’s broken from the pack.

Sen. John McCain, R-Az., isn’t just voicing his disappointment of the likely use of the nuclear option. The Arizona senator is calling anyone who thinks the rule change is a good idea a “stupid idiot.”

“I would like to meet that idiot, I’d like to meet the numskull that would say that,” McCain told reporters Tuesday. “That after 200 years, at least 100 years of this tradition, where the Senate has functioned pretty well, they think it would be a good idea to blow it up.”

McCain said that a permanent change to Senate rules for the sole purpose of getting Trump’s nominee confirmed would be a “body blow to the institution,” and would lead the Senate down a slippery slope.

“Whoever said that is a stupid idiot who hasn’t been here and seen what I’ve been through and how we’ve been able to avoid that on several occasions — they’re stupid and have deceived their voters because they’re so stupid,” he raved.McCain was referring to similar situations in the past, where presidential nominees faced partisan filibusters. He cited the “Gang of 14” in 2005 that managed to avoid a permanent rule change. But “the atmosphere is different” today, according to the Arizona senator.

Senate Majority Leader Mitch McConnell said Tuesday that the GOP’s likely use of the nuclear option was in response to the Democrats’ Senate rule change in 2013.

He added that “it’s a fairly recent thing to filibuster executive branch appointments,” and that the upcoming rule change will “even that up so the Supreme Court confirmation process is dealt with just like it was throughout the history of the country.”

And according to McConnell, Democrats are “pretty locked in” on their threat to filibuster Gorusch.

“I think they’re responding to their base, which says ‘Resist everything.’ It’s particularly ridiculous to watch it on Gorsuch because there are no good arguments to vote against Gorsuch. None whatsoever,” he said.